You may reveal a card with assist kicker and discuss how to pay for it before you begin to cast the spell
Yes, White is more than just knights, clerics and the odd angel or pegasus
6 Add: Gilgamesh, Master-At-Arms The Legendary Summon Synergizes Perfectly With The Rest Of The Deck While he does not appear in the original game, Gilgamesh does appear as a secret boss in FF7 Rebirth , so adding Gilgamesh, Master-at-Arms would not only be beneficial to the deck, but it would also, technically, stay on theme with the rest of the cards
Or you could try Sazhs Chocobo into Sidequest: Raise a Chocobo, play Prishes Wanderings or Summon: Fenrir as a reasonable turn three combat enhancer, and then drop turn four Summon: Fat Chocobo and flip your Sidequest for an almost unbeatable board lead